Various devices have been developed to control and/or monitor a site from a remote location. For example, many fire alarm systems in high rise buildings include the functionality to alert a remotely located fire station if a fire is detected in such buildings. Specifically, such a fire alarm system commonly includes a plurality of remote smoke/fire detectors and alarms that all are directly connected (e.g., via a twisted pair) to a central control panel. When one of the detectors senses a fire and/or smoke in the building, it transmits a signal to the central control panel, which consequently sets off the alarms. People who hear the alarms thus may evacuate the building.
The central control panel may include a modem that transmits a signal to the fire station when one or more of the remote detectors senses a fire. This signal is a direct circuit switched connection via the public switched telephone network (“PSTN”). To establish such a connection, the fire station must have a modem that can communicate with the modem on the central control panel. Problems arise, however, when something goes wrong at the fire station, or when the PSTN suffers some kind of link failure. In such case, the signal to the fire station is not properly transmitted to the fire station, thus eliminating the intended benefit of such a connection.
This type of alarm system also has service problems. Namely, if there is a mechanical problem with the fire alarm system, then the company servicing the system cannot diagnose the problem remotely. Accordingly, a technician must be sent to the building, thus incurring travel cost.